Texas Attorney General Kenneth Paxton (2nd R) in front of the U.S. Supreme Court in April. (Photo by Alex Wong/Getty Images)

Texas Attorney General Ken Paxton warned Monday that the Obama administration’s new rules reducing carbon emissions from power plants would hurt the Texas grid.

“This rule will inevitably raise rates and reduce reliability for everyone,” he said. The Clean Power Plan “represents an unprecedented extension of federal authority.”

The comments came on the eve of opening arguments before the D.C. Circuit Court of Appeals to decide whether the president’s effort to slow climate change is within the bounds of the law. Paxton, alongside West Virginia Attorney General Patrick Morrisey and other attorneys, was speaking at a panel in Washington hosted by the Texas Public Policy Foundation and Americans for Tax Reform.

Texas and more than 20 other states have sued the U.S. Environmental Protection Agency, arguing it was assuming authority it had never been granted when Congress passed the Clean Air Act in the 1970s.

In a question and answer session with the audience, Paxton offered a dismissive appraisal of the president’s carbon reduction plan.

“Sometimes truth is stranger than fiction. If I had written this before it happened, no one would have believed me,” he said.